

For the same reasons Lemmy is federated:
- Resilience - if one server goes down, only that one artist’s music becomes unavailable
- Control - if the artist owns the server, they can control it/moderate it as they see fit
You can’t really count on either of those things if you’re putting your music up on Spotify, Tidal, etc.
Edit: there would be nothing stopping several artists from handing together and hosting all their music from a single server/instance, if they wanted to. That’s the point though, there’s choice
Right, ActivityPub would really just be the discovery mechanism, obviously you wouldn’t want the actual music to be mirrored to other instances.
If you use a centralized discovery server, you’re right back to where you are with Spotify - at the mercy of whoever controls the discovery server, and shit out of luck if the discovery server goes down. Federation is only confusing for normies because the clients for popular fediverse apps don’t do a good job of making that part clear (or hiding it away).